The potential of antagonistic moroccan Streptomyces isolates for the biological control of damping‐off disease of pea (Pisum sativum L.) caused by Aphanomyces euteiches

Abstract

Three hundred and fifty‐nine isolates of actinobacteria collected from different Moroccan soils were evaluated for their in vitro antimicrobial activity against the oomycete pathogen Aphanomyces euteiches, the causal agent of damping‐off of pea and other legumes. Eighty‐seven isolates (24%) had an inhibitory in vitro effect against A. euteiches. Fourteen bioactive isolates with the greatest inhibitory effect against A. euteiches and no inhibitory effect on plant beneficial rhizobia were tested for their ability to protect pea seeds and seedlings against the damping‐off disease using culture supernatants or spore suspensions as treatments. The two most protective isolates, OB21 and BA15, significantly reduced, compared to untreated control plants, damping‐off by 33% and 47%, respectively. The two bioactive isolates were classified as species of the genus Streptomyces based on 16S rDNA analysis and morphological and chemical characteristics.

Diversity and Antimicrobial Activities of Actinobacteria Isolated from Mining Soils in Midelt Region, Morocco

“…From the unexplored hot Merzouga desert, one hundred and sixty-three Actinobacteria isolates were obtained, of which 59% showed a high biological diversity with the greatest growth inhibition of pathogens tested [ 21 ]. The study reported by Oubaha et al shows that Streptomyces species isolated from rhizospheric soils displayed a potent inhibitory effect against Aphanomyces euteiches causing the damping‐off disease of pea ( Pisum sativum L.) [ 60 ]. However, Actinobacteria from Moroccan mining habitats have not been investigated for their biocontrol potential.…”

Plant Beneficial Microbes Controlling Late Blight Pathogen, Phytophthora infestans

“…Actinomycetes are Gram+ bacteria that represent a high proportion of the soil microbial biomass and have the ability to produce a wide variety of antibiotics and of extracellular enzymes. Several strains of actinomycetes have been found to control plant diseases [59][60][61]. Recently, [62] were identifed β-rubromycin as a P. infestans cyst germination inhibitor by screening compounds produced by Streptomyces isolated from soil.…”

Isolation and identification of endophytic actinobacteria from Iris persica and Echium amoenum plants and investigation of their effects on germination and growth of wheat plant

“…Biological interactions between plants and endophytic microorganisms may cause reduced amounts of biological stressors. In fact, metabolic studies have shown that endophytic microorganisms play a role in strengthening and growing plants by stimulating the production of plant hormones such as auxins and gibberellins, or as plant protection agents against microbial pathogens and insects (Ek‐Ramos et al, 2019 ; Oubaha et al, 2019 ). In a research conducted in 2014, it was observed that the overexpression of malic acid‐producing genes in the endophytic bacterial strains increased the release of phosphate in the soil, and as a result led to higher number of lateral branches with higher length of the stem and roots in wheat plants (Jog et al, 2014 ).…”